Tin-: STAINING OF SOIL PROTOZOA. 



BY J. FRANKLIN MORGAN. 



In the litpi-atiuv, several stains are meuUuiied Un- the staininj^ uf 

 soil protozoa. 



Goodey^ for an intra vitam stain of these organisms, Las fonnd 

 neutral red (1-100,000) very nsefnl for showing np the food vacuoles, 

 and methylene green very serviceable for quickly bringing out the 

 nuclei. 



^Martin-, mentions the use of iron haemotoxylen for the staining 

 of the nucleus and blepharoplas.t. Later, in anotlier article'', he 

 uses a strongly acid hiimalun followed by eosin. 



The writer has had no experience Avith any of the above, but would 

 like to add another method for the staining of soil ])rotozoa. 

 This is used as a difterential staining for other protozoa such as 

 trypanosomes and parasites of the blood. 



This stain is a modified form of the Komanowski — one that is 

 used in the bacteriological laboratories of the University of Michi- 

 gan. It consists of three stains: Polychrome methylene blue, methy- 

 lene blue and eosin. 



I'RKPARATION OF STAIN. 



A. Polychrome methylene blue. 



Methylene blue 1 gm. 



Sodium carbonate (anhydrous) 0.25 gm. 



Glvceriue 50 cc. 



Distilled water ^ 50 cc. 



This mixture is heated for one hour between 88-90°C with con- 

 stant stirring. Five cubic centimeters of water is added every 10 

 minutes to make up the loss due to evaporation. IJefore the heat- 

 ing and again after the healing when cool, the beaker with its con- 

 tents is weighed. The deficiency is made up with distilled water. 

 When complete, this stain ought to be of a purplish or azure color. 



1. Goodev. T., "Contribution to Our Knowledge of Protozoa of the Soil," Proc. 

 Ilov. Sop. of London. 1011, 84 B. p. lOr,. 



2. Martin, "rrotozoa from Hick Soils." Proc. Roy. Soc. of London, 1912. 85B. p. 393. 

 8. Martin. "Tin- Prpscnco of Protozoa In Soils," Nature, 1913, Vol. 91, No. 2266, 



p. 111. 



